Tel 2 light stays lit on modem

The Tel 2 light stays lit on my moden for weeks at a time. Tel 2 light was lit on 11-1-18 and I noticed it was off on 11-20-18. Then on 11-21-18 it was lit again, and has been lit ever since. This year I had tech come to home for another problem but while he was there I asked him about the Tel 2 light being lit since I only have 1 phone line. I was told, by the tech, that Comcast runs reports early in the morning. However, the Tel 2 light stays on all the time. Tel 2 light is not flashing but is solid just like the Tel 1 light. The only documentation I have of the Tel 2 light flashing is on 10-02-18. There is nothing plugged into the Tel 2 port in back of the modem.